Upright vacuum cleaners employ a variety of dirt separators to remove dirt and debris from a working air stream. Some upright vacuum cleaners employ cyclone separators. Some cyclone separators use one or more frusto-conical-shaped separator(s) and others use high-speed rotational motion of the air/dirt to separate the dirt by centrifugal force. Typically, working air enters and exits at an upper portion of the cyclone separator as the bottom portion of the cyclone separator is used to collect debris. Before exiting the cyclone separator, the working air may flow through an exhaust grill. The exhaust grill can have perforations, holes, vanes, or louvers defining openings through which air may pass.
Upright vacuum cleaners can also employ filter bag separators. Typically, working air is either forced through or drawn through an air permeable filter bag leaving the debris entrained in the working air path inside the filter bag.